1. Field of the Invention
This invention relates to novel methods for fiber finishing. In particular, the present invention relates to methods of imparting lubricity to fibers.
2. Description of the Related Art
Generally, in the case of many fiber materials, finishing compositions are applied to fibers to improve their subsequent handling and processing. Fiber finishes, in part, enable a fiber producer to manufacture a fiber product and in turn enable a purchaser of that product to utilize yarn and fabric manufacturing processes to obtain an end product. The composition and amount of a particular fiber finish applied depend in large measure upon the chemical characteristics of a particular fiber, the particular stage in the processing of the fiber at which it is applied, and the envisioned use of the particular fiber.
Such finishes generally provide lubrication, prevent static build-up, and afford a slight cohesion between adjacent fibers. Many other characteristics, however, are also desirable. For example, they should be easily applied to and removed from fibers and should be useful in subsequent treatment of the fibers. Also, they should have desirable thermal and chemical stability while not adversely affecting the fibers themselves. Such fiber finishes should not leave residues on objects they come in contact with nor cause toxic fumes or undesirable odors. They should provide for rapid wetting of fiber surfaces, be water-soluble or emulsifiable or solvent-soluble, and have good storage stability. Further, they should not attract soil, cause color changes to fibers, interact with frictional elements used in texturizing or be corrosive to machine parts.
Application of such finishes may generally be accomplished by contacting a fiber tow or yarn with a solution or emulsion comprising at least one lubricant having desirable antistatic properties. Additional antistatic agents, wetting agents, additives such as antioxidants, biocides, anti-corrosion agents, pH control agents, as well as emulsifiers are also commonly found in such finishes. A suitable fiber finish may also be sprayed or applied directly onto fibers or yarn.
In the past, fiber finishes were composed of many elements in addition to a lubricant with each element imparting a desirable characteristic to the fiber finish. For example, in addition to the lubricant, antistatic agents were often added to increase the ability of the fiber to avoid buildup of static electric charge. Also emulsifiers were often added to aid in the application to the fiber of the often oily and unmanageable lubricant.
Various lubricating agents have been disclosed by Ogiso et al. U.S. Pat. No. 4,615,816, Yamamoto et al. U.S. Pat. No. 4,505,956, Carver U.S. Pat. No. 3,951,825, Carver U.S. Pat. No. 3,907,689, Koleske U.S. Pat. No. 4,163,114, and Sturwold et al. U.S. Pat. No. 3,970,569. Various fiber finishes have been disclosed by Crossfield et al. U.S. Pat. No. 4,098,702 and Murase et al. U.S. Pat. No. 4,403,049. Casciani U.S. Pat. No. 4,766,153 discloses certain alkyl polyoxy alkylene carboxylates which are surface active agents and stated that they are suitable as emulsifiers, dispersing agents, lubricants, wetting agents, levelling agents, and the like in the textile industry, e.g. as wetting, softening or lubricating agents. In addition, ether carboxylate esters have also been employed as plasticizers. See Bell et al. U.S. Pat. No. 2,803,646 and North U.S. Pat. No. 2,109,947.
While these efforts may be satisfactory, they all involve the use of emulsifiers and sometimes they are difficult to handle due to the viscosity of some compounds. Accordingly, a more desirable method is indicated which can impart desirable properties, e.g. lubricity, in fiber finishes. Such a method should be able to be applied to a fiber with little or without the use of emulsifiers while imparting desirable characteristics, e.g. lubricity.